The encryption and decryption of computer data is widely known and used. For example, data is often encrypted for information protection before it is stored or transmitted across a network, and is then subsequently decrypted for use.
Known techniques for performing encryption and decryption fall into two categories, namely those using software and those using dedicated hardware.
Software techniques, in which data is encrypted/decrypted in accordance with stored computer software instructions, are widely used since they provide the advantage that the software instructions can be executed to encrypt/decrypt data of different types and from different data paths within the computer. The problem with such software techniques, however, is that, the encryption/decryption is time consuming and/or requires considerable processing resources.
Dedicated hardware for performing encryption/decryption is used in computer input/output devices, such as network cards etc. This enables data encryption/decryption to be performed quickly, but suffers from the problem that dedicated hardware must be provided for each data path on which data is to be encrypted/decrypted. This considerably reduces the practicality of using dedicated hardware and makes it inflexible for encryption/decryption.